Safety plug and receptacle



April 10, 1956 5. SMITH SAFETY PLUG AND RECEPTACLEI Filed March 31, 1954 Stephen Smith INVEN TOR.

United States Patent SAFETY PLUG AND RECEPTACLE Stephen Smith, White Plains, N. Y.

Application March 31, 1954, Serial No. 420,061

1 Claim. (Cl. 339-489) This invention relates to a safety plug and receptacle and more specifically provides for safely, quickly, and effectively connecting and locking the end of an electrical conductor.

An object of this invention is to provide a safety plug and receptacle having interengaging prongs and contacts for interlocking the plug and receptacle upon relative rotation between such members.

A further object of this invention is to provide a safety plug and receptacle having telescopically received male and female members with rotatively engaged interlocking means between the male and female members.

Yet another object of this invention is to provide a safety plug and receptacle which is simple in operation, simple in construction, insulated, well adapted for its purposes and relatively inexpensive to manufacture.

These, together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

Figure 1 is a perspective view showing the safety plug and receptacle of the present invention;

Figure 2 is a group perspective showing the male and female members of the safety plug and receptacle of the present invention in disassembled relation;

Figure 3 is a longitudinal, vertical section taken substantially along section line 33 of Figure 1, showing the details of construction of the assembled safety plug and receptacle;

Figure 4 is a transverse section taken substantially along section line 4-4 of Figure 3 showing the details of construction of the interengaging contacts and extending prongs; and

Figure 5 is a detailed transverse section taken sub stantially along section line 5-5 of Figure 2 showing further details of construction of the female member of the safety plug and receptacle.

Referring now specifically to the drawings, it will be seen that the safety plug and receptacle of the present invention is generally designated by the numeral and includes a female member 12 and a male member 14 with a cap 16 and 18 positioned over the remote ends of each of the members 12 and 14.

The female member 12 includes a generally cylindrical tubular member 20 comprising an internally reduced end portion having a pair of internally extending arcuate shoulders 22 which are positioned oppositely on the inner periphery of the tubular member 20. A cylindrical body or platform member 24 is positioned within the tubular member 20 in spaced eccentric relation thereto and fixed between the shoulders 22. A centrally extending guide post 26 extends from one end of the platform 24 toward the inner end of the tubular member 20. The peripheries of the platform 24 and the tubular member 20 are in spaced relation and the two oppositely disposed shoulders 22 form arcuate access grooves 28 for a purpose described hereinafter. A pair of resilient contact members 30 are mounted longitudinally on.

the periphery of the platform 24 and terminate at their inner ends in U shaped circumferentially extending clips or contact members 32 having a flared end portion 34 anchored in grooves 36 in the inner periphery of the tubular cylinder 20. Screw fastening means 38 are provided on the outer end of each of the contact members 30 for securing electrical conductors 40 thereto. The cap 16 positioned over the outer end of the cylindrical tube 20 is provided with a suitable aperture 42 for the passage of the electrical conductors 40 thereby completely insulating the electrical conductors 40 and the contact members 30. Further, it will be seen that the contact members 30 and the U-shaped contacts 32 are so positioned on the platform 24 that they are disposed behind the shoulders 22 for a purpose described hereinafter.

Referring now specifically to the male member 14, it will be seen that the male member 14 is generally a cylindrical plug having a centrally located socket 44 for telescopically receiving the guide post 26 when the body 14 of the male member is telescopically received in the tubular member 20. Prongs 46 having hook-shaped or offset ends 48 are provided on the inner end of the male member 14 and the prongs 46 are generally arcuately curved about an axis formed by the longitudinal center of the safety plug and receptacle 10. The prongs 46 extend completely through the body 14 and suitable screw fastening means 50 are provided for the connection of electrical conductors 52 which proceed through an aperture 54 positioned in the cap 18.

After the conductors 52 and 40 are connected to the screw threaded means 50 and 38, respectively, the male member 14 is inserted into the female member 12 with the guide post 26 entering the tubular socket 44. The ofiset end portions 48 of the prong 46 must be aligned with the arcuate grooves 28 formed by the shoulders 22 thereby permitting entry behind the shoulders 22. After the end portions 48 have been inserted through the grooves 28, the male and female members are rotated in relation to each other thereby engaging the free ends 48 of the prongs 46 with the U-shaped contacts 32 thereby securely contacting the prongs 46 and the contacts 36 and locking the male member 14 in the female member 12. Obviously, the caps 16 and 18 completely insulate the device and the internal construction may be any suitable plastic or insulating type material.

From the foregoing, the construction and operation of the device will be readily understood and further explanation is believed to be unnecessary. However, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the appended claim.

What is claimed as new is as follows:

An electric cord connector comprising separable male and female members, said female member including a tube comprising an internally reduced end portion including diametrically opposite shoulders on its inner periphery spaced inwardly from the adjacent end of the tube and defining a pair of grooves, a cylindrical body mounted longitudinally in the tube in spaced, concentric relation thereto and projecting therefrom, said body being aflixed to the shoulders and including a reduced end portion constituting a guide extending longitudinally in the tube, elongated contacts mounted longitudinally on the projecting portion of the body and extending into the reduced end portion of the tube, said contacts comnrising circumferentially extending, substantially U- shaped resilient clips on the inner ends thereof located behind the shoulders and having one end anchored in the reduced end portion of the tube, said male member comprising a plug rotatably and slidably mounted in the tube in abutting engagement with the internally reduced end portion thereof and having a socket therein accommodating the guide, prongs on said plug operable in the grooves and including circumferentially extending end portions engageable in the clips behind the shoulders for electrically and detachably securing the male and female members together, and apertured closure caps on the end portions of the tube.

References Cited in the file of this patent UNITED STATES PATENTS 1,593,985 Nielsen July 27, 1926' 10 2,123,422 Kautz July 12, 1938 2,245,294 Pelissier June 10, 1941 

